(1) Field of the Invention:
The present invention relates to air ride suspension systems for vehicles having a bolster beam pivotally connected to a hanger and supporting a vehicle axle, where the bolster beam bears the load of the vehicle without loading its pivot connection to the hanger.
(2) Description of the Related Art:
Air ride suspension systems of the type provided by the present invention commonly comprise a pair of hanger members suspended from opposite sides of the vehicle chassis. A beam/axle seat assembly supporting an axle seat and vehicle axle at one end is pivotally connected to each hanger member by a torque rod at its opposite end. An air spring positioned between each beam/seat assembly and the vehicle chassis transmits the vehicle load to the beam/seat assembly.
The pivoting connections of the torque rods between the beams of the beam/seat assemblies and the hanger members controls the pitch of the vehicle axle as it oscillates relative to the vehicle chassis when driving over uneven roads, and maintains the alignment of the drive line with the axle. The torque rods have pivot bushing connections at their opposite ends to the hanger members and the beams. A drawback of this type of arrangement is that many suspension system configurations employing torque rods subject the pivot bushing connections of the torque rods to a portion of the vehicle load. The loading of the pivot bushings substantially reduces their useful life.
It is therefore an object of the present invention to provide a vehicle suspension system utilizing torque rods to control up and down axle movement as the vehicle travels over uneven roads, where the unique configuration of the system minimizes or eliminates a portion of the vehicle load from being carried by the pivot bushings of the torque rods.